1 files changed, 41 insertions, 55 deletions

diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
index 198f062da370..cd37697850cf 100644
--- a/drivers/spi/davinci_spi.c
+++ b/drivers/spi/davinci_spi.c
@@ -91,6 +91,10 @@
 #define SPIFLG_BITERR_MASK              BIT(4)
 #define SPIFLG_OVRRUN_MASK              BIT(6)
 #define SPIFLG_BUF_INIT_ACTIVE_MASK     BIT(24)
+#define SPIFLG_ERROR_MASK               (SPIFLG_DLEN_ERR_MASK \
+                                | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \
+                                | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \
+                                | SPIFLG_OVRRUN_MASK)
 
 #define SPIINT_DMA_REQ_EN       BIT(16)
 
@@ -601,10 +605,10 @@ static int davinci_spi_check_error(struct davinci_spi *davinci_spi,
 static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t)
 {
         struct davinci_spi *davinci_spi;
-        int status, count, ret;
-        u8 conv;
+        int ret;
+        int rcount, wcount;
         u32 tx_data, data1_reg_val;
-        u32 buf_val, flg_val;
+        u32 errors = 0;
         struct davinci_spi_platform_data *pdata;
 
         davinci_spi = spi_master_get_devdata(spi->master);
@@ -612,70 +616,51 @@ static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t)
 
         davinci_spi->tx = t->tx_buf;
         davinci_spi->rx = t->rx_buf;
-
-        /* convert len to words based on bits_per_word */
-        conv = davinci_spi->bytes_per_word[spi->chip_select];
-        data1_reg_val = ioread32(davinci_spi->base + SPIDAT1);
+        wcount = t->len / davinci_spi->bytes_per_word[spi->chip_select];
+        rcount = wcount;
 
         ret = davinci_spi_bufs_prep(spi, davinci_spi);
         if (ret)
                 return ret;
 
+        data1_reg_val = ioread32(davinci_spi->base + SPIDAT1);
+
         /* Enable SPI */
         set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
 
-        count = t->len / conv;
-
         clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
 
-        /* Determine the command to execute READ or WRITE */
-        if (t->tx_buf) {
+        /* start the transfer */
+        wcount--;
+        tx_data = davinci_spi->get_tx(davinci_spi);
+        data1_reg_val &= 0xFFFF0000;
+        data1_reg_val |= tx_data & 0xFFFF;
+        iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
 
-                while (1) {
-                        tx_data = davinci_spi->get_tx(davinci_spi);
+        while (rcount > 0 || wcount > 0) {
 
-                        data1_reg_val &= ~(0xFFFF);
-                        data1_reg_val |= (0xFFFF & tx_data);
-
-                        buf_val = ioread32(davinci_spi->base + SPIBUF);
-                        if ((buf_val & SPIBUF_TXFULL_MASK) == 0) {
-                                iowrite32(data1_reg_val,
-                                                davinci_spi->base + SPIDAT1);
-
-                                count--;
-                        }
-                        while (ioread32(davinci_spi->base + SPIBUF)
-                                        & SPIBUF_RXEMPTY_MASK)
-                                cpu_relax();
-
-                        /* getting the returned byte */
-                        if (t->rx_buf) {
-                                buf_val = ioread32(davinci_spi->base + SPIBUF);
-                                davinci_spi->get_rx(buf_val, davinci_spi);
-                        }
-                        if (count <= 0)
-                                break;
-                }
-        } else {
-                while (1) {
-                        /* keeps the serial clock going */
-                        if ((ioread32(davinci_spi->base + SPIBUF)
-                                        & SPIBUF_TXFULL_MASK) == 0)
-                                iowrite32(data1_reg_val,
-                                        davinci_spi->base + SPIDAT1);
+                u32 buf, status;
 
-                                while (ioread32(davinci_spi->base + SPIBUF) &
-                                                        SPIBUF_RXEMPTY_MASK)
-                                        cpu_relax();
+                buf = ioread32(davinci_spi->base + SPIBUF);
 
-                        flg_val = ioread32(davinci_spi->base + SPIFLG);
-                        buf_val = ioread32(davinci_spi->base + SPIBUF);
+                if (!(buf & SPIBUF_RXEMPTY_MASK)) {
+                        davinci_spi->get_rx(buf & 0xFFFF, davinci_spi);
+                        rcount--;
+                }
 
-                        davinci_spi->get_rx(buf_val, davinci_spi);
+                status = ioread32(davinci_spi->base + SPIFLG);
 
-                        count--;
-                        if (count <= 0)
-                                break;
+                if (unlikely(status & SPIFLG_ERROR_MASK)) {
+                        errors = status & SPIFLG_ERROR_MASK;
+                        break;
+                }
+
+                if (wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) {
+                        wcount--;
+                        tx_data = davinci_spi->get_tx(davinci_spi);
+                        data1_reg_val &= ~0xFFFF;
+                        data1_reg_val |= 0xFFFF & tx_data;
+                        iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
                 }
         }
 
@@ -683,11 +668,12 @@ static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t)
          * Check for bit error, desync error,parity error,timeout error and
          * receive overflow errors
          */
-        status = ioread32(davinci_spi->base + SPIFLG);
-
-        ret = davinci_spi_check_error(davinci_spi, status);
-        if (ret != 0)
+        if (errors) {
+                ret = davinci_spi_check_error(davinci_spi, errors);
+                WARN(!ret, "%s: error reported but no error found!\n",
+                                                        dev_name(&spi->dev));
                 return ret;
+        }
 
         return t->len;
 }